Trojan wars

You advise readers to click on a link in an email only if it comes from a trusted contact (20 March, p 20). Never click on such links. You should copy the linked address and paste it into a plain-text editor, and learn how to examine it for suspicious signs.

Mostly, it will be harmless. But one time your trusted contact will have had their computer hacked, and it will have sent emails to everyone in their address book. Following the link in that email may take you to a site that in turn hacks into your machine, and makes it send emails to all your contacts.

To continue reading this article, subscribe to receive access to all of newscientist.com, including 20 years of archive content.

To continue reading this article, log in or subscribe to New Scientist